add clara_train_covid19_3d_ct_classification and clara_train_covid19_… (#2455)
add clara_train_covid19_3d_ct_classification and clara_train_covid19_… (#2455)

* add clara_train_covid19_3d_ct_classification and clara_train_covid19_annotation_ct_lung_1

point to pt version of covid19 lung annotation model

Signed-off-by: Holger Roth <3dd32d6f42aab1f9494aa5592e1b40efd678364d@nvidia.com>
Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI